Process of obtaining fast-colored discharges on fast dyeings



Patented Aug. 9, 1927.

UNITED STATES PATENT OFFICE.

nrns'rorr conromi'rr'oif, or NEW YORK,

N. Y., A CORPORATION OF DELAWARE.

PROCESS OF OBTAINING FAST-COLORED DISGHARGES 011' EAST DYEINGS.

No Drawing. Application filed January 16, 1926, Serial No. 81,831, and in Germany January 19, 1925.

It has already been known for a long time that vat-dyestuffs can be used as colored discharges on dyeings which are obtained by meansof azo-dyestufis. In these (118- charge styles the dyed ground is, naturally,

considerably less fast than thecolored discharges used and, moreover, the vat-dyestuffs have the tendency to form halos. Furthermore vat dye stufis are likewise used 30 as colored discharges on indigo. In this case the dyed ground is also not so fast as the colored discharges printed thereon.

I have now found that a discharge style of unexcelled fastness can be obtained by producing the 'dyeing by means of vat dyestufi's which are destroyed by a reducing agent such as, for instance, formaldehyde sulfoxylate to which Leucotrope W cone. is added, and by using as colored discharges vat dyestuffs which sufliciently resists the action of the said reducing agent. Leucotrope W cone. is the calcium salt of the disulfonic. vacid obtained by sulfonating dimethylpheny1-benzylammonium chloride described in Schultz. Farbstoiftab'eTlen 6th ed., vol. 2, page 200. An essential point in my new process is that only so much of the formaldehyde sulfoxylate with Leucotrope added thereto should be used as is necessary for discharging the dyed ground and for reducing the dyestufl in the colored discharge without,

destroying it. In the new discharge style the colored discharges obtained by means of vat dyestuffs have the further advantage of forming no halos. y The following examples serve to illustrate my invention: (1) The material dyed with 4% of indan threne olive R paste is printed with the fol- 40 lowing colored discharge:

Colored discharge.

130 gr. of indanthrene orange RRT. 600 gr. of standard color.

80 gr. of Leucotro e W conc. 40 gr. of anthraquinone paste. 150 gr. of water.

lkilo Standard color.

of zinc oxide.

of glycerine.

of dissolving salt B.

of wheat-starch tragacanth-thickenof pota sium carbonate.

of hydrosulfite N. F. cone. 2 parts hydrosulfite to 1 part of water.

gr. 30 g1. 30 gr. 200 gr.

120 gr. 150 gr.

600 grams.

00Zored discharge.

I 50 gr. of indanthrene blue 3 G paste fine. 150 gr. of indanthrene yellow G double paste 600 gr. of standard color (prepared as indi cated in Example 1.

100 gr. of Leucotrope W conc.

100 gr. of water.

1 kilo (3) The material dyed with 4% of indanthrene brown G paste 7.5% of indanthrene yellow RK paste and 0.5% of indanthrene reddish-violet RK paste is printed with the following discharge and then further treated as indicated in Example 1:

150 gr. of indanthrene violet BN paste fine.

600 gr. of standard color (pre ared as indicated in Example ll gr. of Leucotrope W conc. 190 gr. of water.

1 kilo.

(4) The material dyed with 30% of Helindone fast scarlet B is printed with the following colored discharge and further treated as indicated in Example 1:

' 200 gr. of ililiganthrene brilliant blue R paste as are destroyed by reducing agents with the e. t addition of the calcium salt of the dissul- 600 gr. of standard color (prepared as indifonic acid obtained by sulfonating dime- 15 cated in Example 1). thylphenyl benzyl ammonium chloride, and 5 80 gr. of. Leucotrope W. cone. by using for the colored discharges such vat 120 gr. of water. 1 dyestuffs as sufliciently Withstand the said discharging agents. 1 kilo. 2. Material dyed according to the process 20 I claim: set forth in claim 1. 1. Process of obtaining fast colored dis- In testimony whereof, Iaflix my signature.

charges on fast dyeings by using such vat dyestuffs for the dyeings to be discharged WILLIAM COTTON. 

